A question for EMD buffs....

[Anonymous]

What is so different from the SD70MAC and the SD90/45MAC, and the new SD70ACe?

One thing about it, the engine has HUGE flares and an even uglier nose than its predecessors!

[Anonymous]

i think the SD70ACe has a new different stlye of motor..its still rated at 4,000 HP though, and the external differences obviously..i think its ugly as hell, lol

[M636C]

OK,

The engine is much the same, an EMD 16-710G3 with variations in all three units. In the SD70MAC it develops 4000HP at 904 rpm, in the SD90/43 and in the SD70ACe, it develops 4300HP at 950 rpm. The fine detail is different between the last two, because the SD70ACe has to meet more stringent emissions controls.

The cab on the SD70ACe is based on the cabs on the last SD90s, and much of the layout of the SD70ACe, such as the location of the dynamic brake, is similar to the SD90. The SD70ACe is a lot shorter than the SD90, and some of this appears to be due to EMD adopting a new location for the inverters (the electrical equipment that produces the variable frequency AC for the motors), in a compartment outside the hood behind the cab on the left hand side. This arrangement is similar to the GE AC4400 and AC6000. It is likely that the radiators are somewhat smaller than the SD90, since they only have to handle 4300HP rather than 6000HP, as all SD90s were designed to take the EMD 16-265H engine at some time.

I am told that the actual frame is made from lighter sections but is deeper to compensate for this, and this makes the whole locomotive slightly taller. This is similar to the CN GP40-2Ws, some of which had a "lightweight" frame and were taller than the standard units.

Along with the new inverter location, it is said that EMD have adopted another GE idea, of having most of the air brake equipment and piping on one side of the unit and most of the electrical cabling on the other side.

But I really hope they don't keep the cab design, it really is uglier than all of their other designs. I was told it used the same front windows as a GE cab, to save the railroad on the cost of keeping spares.

Peter

[Allen Jenkins]

Don't forget the new Federal Tier II Emissions Regulations, which ultimately demanded the use of the 16V710 Series prime mover. I've heard the desktop controller is out, for the NS type bi-directional short hood forward "haulway" like on the Robert McKee add for ITT Tech.(He's my hero). Enjoy Your Locomotive Trip...ACJ

[AntonioFP45]

I like those flares!!!!!!!

To me it looks like an EMD SD45 that muscled up and "HULKED OUT"!

Regarding the new nose: In thinking about it I spent years looking at EMD "Spartan Cabs" on GP35s, GP38s, GP40s, SD45s, etc. I like the EMD safety cabs because they so much resemble the F45/ FP45/ SDP40f/ F40C cabs.

Overall even though that new nose is much less attractive, IMHO, to me it is still better looking than the old Spartan Cabs. The Spartan cabs remind me too much of highway truck cabs.[:p]

Roger that![;)]

[jeffshultz]

The new cab was created in response to user (read: hogger and conductor) feedback. Apparently they disliked bumping their heads on the older, shorter one. Since they are EMD's customers, not the railfan community, I'm guessing you'd better get used to the new cab.

The reason for the new models is Tier II, plain and simple.